Periodontal dental composition

ABSTRACT

A periodontal dental composition is disclosed comprising folic acid and a polishing agent which is principally dicalcium phosphate.

Folic acid is a well known anti-irritant and anti-inflammatory material.A normal adult requires at least about 0.3 mg of this material in orderto maintain oral health. Folic acid is a conjugate bound to up to sevenmolecules of glutamic acid. It has the structural formula: ##STR1##

It was reported by R. Vogel et al of New Jersey Dental School, Newark,N.J., in AADR Abstracts 1977, 34 "Effect of Folic Acid Rinse On GingivalHealth" and IADR Abstracts 1977, 565 "Folic Acid and ExperimentalProduced Gingivitis", that folic acid can be directly absorbed by thegingiva from a rinse solution resulting in a significant reduction ingingival inflammation.

Unfortunately, when a dental preparation is formulated including adentally acceptable water-insoluble polishing agent the retention ofsoluble folic acid available to be absorbed in the gingiva can besubstantially reduced.

According to the present invention a periodontal dental compositioncomprises folic acid and a polishing agent which is principallydicalcium phosphate.

The periodontal dental composition comprising folic acid and polishingagent is typically a dental cream. The initial pH of the preparation maybe about 4-10, preferably about 6-9 (on a 20% slurry). Below a pH ofabout 4, large amounts of folic acid would be removed.

Folic acid is typically present in amount of about 0.01-5% by weight,preferably about 0.05-0.5%.

Various water-insoluble polishing agents which are normally dentallyacceptable cause removal of at least a portion of the folic acid fromsolution in the composition. For instance, sodium aluminosilicate (e.g.of low alumina content; essentially sodium silicate with a small amountof combined alumina) and insoluble sodium metaphosphate may causeinsolubility or remove about 70% or more of the folic acid upon agingfor 3 months at room temperature and at 43° C. Lesser, but stillmeaningful amounts of folic acid (e.g. about 15-25%) may beinsolubilized or removed when the polishing material is hydrated alumina(e.g. alpha-alumina trihydrate) or calcium carbonate.

It has however been found that the polishing agent dicalcium phosphatepermits high retention of soluble acid when it is the principalpolishing agent. Indeed, when dicalcium phosphate, as the dihydrate oranhydrous salt, or as a mixture of both, is substantially the solepolishing agent compatibility with folic acid of up to 100% can beachieved upon aging for 3 months at room temperature, as well as oftenat 43° C.

The polishing agent typically comprises 20-75% by weight of the dentalcomposition, preferably 20-55% by weight. Dicalcium phosphate is theprincipal component of the polishing agents; i.e., it comprises morethan half to substantially all of the polishing agent.

The dental composition can be a cream or gel with liquids and solidsproportioned to form a creamy or gel mass of desirable consistency. Ingeneral, liquids in the composition comprise chiefly water andhumectants such as glycerine, sorbitol, propylene glycol, polyethyleneglycol (e.g. molecular weight about 600) or the like, including suitablemixtures thereof. It is advantageous usually to use a mixture of bothwater and a binder or humectant such as glycerine and/or sorbitol. It ispreferred to use at least about 30% liquid, preferably for a cream about10-50% water, and about 20-80% humectant.

The solid portion of the vehicle is a gelling agent, such as the naturaland synthetic gums and gumlike materials, such as Irish moss, gumtragacanth, alkali metal carboxymethyl cellulose and hydroxyethylcarboxymethyl cellulose, polyvinyl pyrrolidone, starch, xanthan,water-soluble hydrophilic colloidal carboxyvinyl polymers, such as thosesold under the trademark Carbopol 934 and 940 and synthetic inorganicsilicated clays such as those sold under the trademark Laponite CP andLaponite SP. These grades of Laponite have the formula

    [Si.sub.8 Mg.sub.5.1 Li.sub.0.6 H.sub.7.6 O.sub.24 ].sup.0.6- Na.sup.+ 0.6

The solid portion of the vehicle is typically present in an amount up toabout 10% by weight of the dentifrice and preferably about 0.5-5% byweight. When employed, grades of Laponite are preferably used in amountsof about 1-5% by weight.

Organic surface-active agents may be used in the composition of thepresent invention to achieve increased prophylactic action, assist inachieving through and complete dispersion of the instant compositionsthroughout the oral cavity, and render the instant compositions morecosmetically acceptable. The organic surface-active material may beanionic, nonionic, ampholytic or cationic in nature, and it is preferredto employ as the surface-active agent a detersive material which impartsto the composition detersive and foaming properties. Suitable types ofsuch detergents are water-soluble salts of higher fatty acidmonoglyceride monosulphates, such as the sodium salt of themonosulphated monoglyceride of hydrogenated coconut oil fatty acids,higher alkyl sulphates, such as sodium lauryl sulphate, alkyl arylsulphonates, such as sodium dodecyl benzene sulphonate, olefinsulphonates, such as sodium olefin sulphonate in which the olefin groupcontains 12-21 carbon atoms, higher alkyl sulphoacetates, higher fattyacid ester of 1,2-dihydroxy propane, sulphonates, and the substantiallysaturated higher aliphatic acyl amides of lower aliphatic aminocarboxylic acid compounds such as those having 12 to 16 carbon atoms inthe fatty acid, alkyl or acyl radicals and the like. Examples of thelast mentioned amides are N-lauroyl sarcosine, and the sodium,potassium, and ethanolamine salts of N-lauroyl, N-myristoyl orN-palmitol sarcosine, which should be substantially free from soap orsimilar higher fatty acid material which tends to substantially reducethe effect of these compounds in compositions of the present invention.The amides are particularly advantageous since they exhibit a prolongedand marked effect in the inhibition of acid formulation in the oralcavity due to carbohydrates breakdown in addition to exerting somereduction in the solubility of tooth enamel in acid solutions. Anotherdesirable material is a long chain fatty acid sodium monoglyceridesulphonate used alone or in combination with sodium lauryl sulphate.

Other particularly suitable surface-active materials include nonionicagents such as condensates of sorbitan monostearate with approximately60 moles of ethylene oxide, condensates of propylene glycol("Pluronics") and amphoteric agents such as quaternized imidazolederivatives, which are available under the trademark "Miranol" such asMiranol C₂ M. Cationic surface-active germicides and antibacterialcompounds such as di-isobutyl phenoxy ethoxy ethyl dimethyl benzylammonium chloride, benzyl dimethyl stearyl ammonium chloride, benzyldimethyl stearyl ammonium chloride, tertiary amines having one fattyalkyl group (of from 12-18 carbon atoms) and two (poly) oxyethylenegroups attached to the nitrogen (typically containing a total of fromabout 2 to 50 ethanoxy groups per molecule) and salts thereof withacids, and compounds of the structure ##STR2## where R is a fatty alkylgroup containing from about 12 to 18 carbon atoms, and x, y and z total3 or higher, as well as salts thereof with mineral or organic acids, mayalso be used. It is preferred to use from about 0.05 to 5% by weight ofthe foregoing surface-active materials in the instant oral compositions.

Any suitable flavoring or sweetening materials may be employed informulating a flavor for the composition of the present invention.Examples of suitable flavoring constituents include the flavoring oils,e.g., oils of spearmint, peppermint, wintergreen, sassafras, clove,sage, eucalyptus, marjoram, cinnamon, lemon and orange, as well asmethylsilicylate. Suitable sweetening agents include sucrose, lactose,maltose, sorbitol, sodium cyclamate, perillartine and saccharine.Suitably, flavor and sweetening agents may together comprise from about0.01 to 5% or more of the compositions of the instant invention.Chloroform may be used too.

The composition of the present invention suitably may also contain afluorine-containing compound having a beneficial effect on the care andhygiene of the oral cavity, e.g., diminution of enamel solubility inacid and protection of the teeth against decay. Examples thereof includesodium fluoride, stannous fluoride, potassium fluoride, potassiumstannous fluoride (SnF₂ KF), sodium hexaflurorostannate, stannouschlorofluoride, sodium fluorozirconate, and sodium monofluorophosphate.These materials which disassociate or release fluorine-containing ionsin water, suitably may be present in an effective but non-toxic amount,usually within the range of about 0.01 to 1% by weight of the watersoluble fluorine content thereof.

The preferred fluorine-containing compounds are sodium fluoride,typically present in an amount of 0.02-2% by weight preferably about0.24%, and sodium monofluorophosphate typically present in an amount of0.076 to 7.6% by weight, preferably 0.8%.

Various other materials may be incorporated in the oral compositions ofthis invention. Examples thereof are coloring or whitening agents ordyestuffs, preservatives, anti-corrosive agents, silicones, chlorophyliccompounds, ammoniated materials such as urea, diammonium phosphate andmixtures thereof and other constituents. Whitening agents, such astitanium dioxide, typically in amounts of about 0.5-2%, may bebeneficial to the appearance of the dental composition, since uponaging, some discoloration may occur.

The adjuvants are incorporated in the instant compositions in amountswhich do not substantially adversely affect the properties andcharacteristics desired and are selected and used in proper amountsdepending upon the particular type of composition involved.

Antibacterial agents may also be employed in the oral compositions ofthe instant invention in an amount of about 0.01-5% by weight. Typicalantibacterial agents include:

N¹ -(4-chlorobenzyl)-N⁵ -(2,4-dichlorobenzyl) biguanide;

p-chlorophenyl biguanide;

4-chlorobenzhydryl biguanide;

4-chlorobenzhydrylguanylurea;

N-3-lauroxypropyl-N⁵ -chlorobenzylbiguanide;

1,6-di-chlorophenylbiguanidohexane;

1,6-bis-(2-ethylhexylbiguanide) hexane;

1-(lauryldimethylammonium)-8-(p-chlorobenzyldimethylammonium) octanedichloride;

5,6-dichloro-2-guanidinobenzimidazole;

N¹ -p-chlorophenyl-N⁵ -laurylbiguanide;

5-amino-1,3-bis(2-ethylhexyl)-5-methylhexahydropyrimidine and theirnon-toxic acid addition salts.

Synthetic finely divided silicas such as those sold under the trademarksCab-O-Sil M-5, Syloid 244, Syloid 266 and Aerosil D200 and mixturesthereof may also be employed in amounts of about 0.5-20% by weight topromote thickening or gelling of the dentifrice.

The following specific Examples are illustrative of the presentinvention. All amounts are by weight unless otherwise indicated.

EXAMPLES 1-3

The following periodontal dental compositions were prepared anddeaerated.

    ______________________________________                                                        1      2        3                                                             PARTS  PARTS    PARTS                                         ______________________________________                                        Glycerine         22.0     22.0     22.0                                      Sodium carboxymethyl                                                          cellulose         0.9      0.9      0.9                                       Tetrasodium pyrophosphate                                                                       0.5      0.5      0.5                                       Sodium fluoride   --       0.24     --                                        Sodium monofluorophosphate                                                                      --       --       0.82                                      Sodium saccharine 0.17     0.17     0.17                                      Water             20.67    20.43    19.85                                     Dicalcium phosphate dihydrate                                                                   48.76    48.76    48.76                                     Flavor            1.00     1.00     1.00                                      Sodium lauryl sulphate (100%)                                                                   1.50     1.50     1.50                                      Folic acid        0.50     0.50     0.50                                      pH                6.9      7.0      6.7                                       ______________________________________                                    

After aging for 3 months at room temperature and 43° C. the followingretention levels of soluble folic acid are observed:

    ______________________________________                                                 % SOLUBLE FOLIC ACID RETENTION                                       COMPOSITION                                                                              ROOM TEMPERATURE  43° C.                                    ______________________________________                                        1          100.0             102.0                                            2          108.0             100.0                                            3          104.0              96.0                                            ______________________________________                                    

Complete retention of soluble folic acid upon aging at room temperatureis also obtained when stannous fluoride (in amounts corresponding to0.1% fluoride) replaces sodium fluoride in composition B. Color ofcompositions 1 to 3 can be improved by adding 1% titanium dioxide toeach.

We claim:
 1. A periodontal dental composition consisting essentially of about 0.01-5% by weight of folic acid and a polishing agent which is principally dicalcium phosphate.
 2. The periodontal dental composition claimed in claim 1 which is a dental cream and has a pH in the range of 4-10.
 3. A periodontal dental composition as claimed in claim 1 wherein 20-75% by weight of polishing agent is present.
 4. A periodontal dental composition as claimed in claim 1 wherein the polishing agent is substantially solely dicalcium phosphate as the dihydrate or anhydrous salt, or as a mixture thereof.
 5. A periodontal dental composition as claimed in claim 1 wherein the dicalcium phosphate is dicalcium phosphate dihydrate.
 6. A periodontal dental composition as claimed in claim 1 wherein titanium dioxide is present. 